Apigee tutorial yahoo oauth_problem

[#1]

Whenever I try to interact with yahooapis, I get the following response:

<yahoo:error xmlns:yahoo="http://www.yahooapis.com/v1/base.rng" xml:lang="en-US" yahoo:uri="http://yahoo.com">

<yahoo:description> Please provide valid credentials. OAuth oauth_problem="OST_OAUTH_PARAMETER_ABSENT_ERROR", realm="yahooapis.com" </yahoo:description>

<yahoo:detail> Please provide valid credentials. OAuth oauth_problem="OST_OAUTH_PARAMETER_ABSENT_ERROR", realm="yahooapis.com" </yahoo:detail>

</yahoo:error>

This same response comes from the first link in the tutorial: <a href="http://weather.yahooapis.com/forecastrss?w=12797282">http://weather.yahooapis.com/forecastrss?w=12797282</a><a href="http://weather.yahooapis.com/forecastrss?w=12797282"></a>

as well as from

http://{org-name}-test.apigee.net/v1/weather/forecastrss?w=12797282

(with org-name replaced, of course)